German patents nos. DE-A 25 16 014 and DE-A 39 39 598 describe a crushing machine, in particular an impact crusher, which comprises a rotor equipped with crushing elements, wherein inside the housing at least one impact mechanism fitted with impact elements is mounted. In order to replace the impact elements, at least part of the housing can be swung around a horizontal axis. A disadvantage of such an apparatus is that it is difficult or impossible to loosen from the outside the impact elements in the area of the impact mechanisms. Moreover problems are encountered with respect to removing the impact elements from the inside of the machine. The same also applies, of course, to the subsequent re-fitting of the impact mechanisms in the reverse mode of operation.